Loading and compression of a single two-dimensional Bose gas in an optical accordion

Abstract

The experimental realization of two-dimensional (2D) Bose gases with a tunable interaction strength is an important challenge for the study of ultracold quantum matter. Here we report on the realization of an optical accordion creating a lattice potential with a spacing that can be dynamically tuned between 11 and 2 $\ensuremath{\mu}\mathrm{m}$. We show that we can load ultracold $^{87}\mathrm{Rb}$ atoms into a single node of this optical lattice in the large spacing configuration and then decrease nearly adiabatically the spacing to reach a strong harmonic confinement with frequencies larger than ${\ensuremath{\omega}}_{z}/2\ensuremath{\pi}=10$ kHz. Atoms are trapped in an additional flat-bottom in-plane potential that is shaped with a high resolution. By combining these tools we create custom-shaped uniform 2D Bose gases with tunable confinement along the transverse direction and hence with a tunable interaction strength.